My theory is that they are not showing m&k footage because they know themselves as a pc gamers that the game supposed to be played with controller and not m&k. They put the option there, because otherwise they would lose a lot of pc gamers but they discourage people to use it at any time.
And yeah, as gopher said, the controls with m&k are "alright", what do you expect him to say? Ofcourse they are "alright", they were "alright" in souls games, but that's not because the implementation is any good, but because m&k is pretty damn good control scheme, especially for those skilled in it. That doesn't change the fact that you probably wouldn't be able to fully control camera distance to the character (which is automatic, again controller feature) etc.
But we need m&k footage to know if there is retardation like mouse smoothing or negative acceleration, not to mention they promised different ui for m&k.
Gonna wait for total biscuit video, he gonna focus on stuff like that.